It depends. If you have massive criminal record and USCIS finds you to be a public safety treat or national security treat , they would report you to ICE once they deny your application. On the other hand, for some odd reason they deny your app - just like these 2 ppl http://tinyurl.com/bukzhta - they will just issue you a denial letter, that would explain why they denied you.
In all case scenario, If you have clean record or minor misdemeanor charges and satisfy DACA requirements, you shouldn't be pulling your hair because they are taking longer than the expected wait period. Relax and keep calm, our approval would come soon.